I just got done putting my car back together, I was rushing to finish up to see if I fixed the problem. I put the batter back in back words and hooked up the terminals, once I realized what I did it was to late. I blew two fuses and now my trailing coil dosn't spark, but it has power.


Does anyone know whats wrong or what I should do
Thanks

 

I just had everything off of the drivers side of the engine bay including the coils, so I don't know if I could have put them back on wrong, but I didnt disconnect any connectors

I could really use some help i ve had the car almost 4 weeks and I drove it two days before broke (87 TII)
thanks

 

....

 

suggestions anyone

 

Check all of the fuses under the hood (driver side mounted on your strut tower), I'm sure you blew the main relay. Replace the ones that are fried including the ones on the drivers side kick pannel (under the dash). Good luck
Jae

 

Replace the trailing coil?

You quite likely did damage to the ECU as well, which will be part of the problem...

 

hopefully the main fuse is what went first, after all, isnt that what its there for? i did the same thing on my first T2, hooked the battery up backwords. lil bit of sparks flew and the car wouldnt work. i checked everything and finaly found out the main fuse was gone. its the middle fuse in the fuse box under the hood. good luck

 

I only blew two fuses under the dash and they were 7.5s i didnt blow any under the hood and I checked the ecu and didn't see any visable signs that it was fried. The car does start and runs but wont rev fast and it doesnt hold an idle.

 

Yeah I would bet you smoked a bunch of the ECU.

You may also need to replace anything electronic on the circuits that you blew fuses on.

 

From what I under stand popping the ECU is not that hard. I did it on my GTUs, my electric fan + grounded to the chassis. That was enough to smoke my ground wire from the motor to the firewall, pop my alt, and take out the ECU. I would double check your grounds and or add a couple of new ones to be safe, replace your fuses, ohm your coil and igniters, then swap the ECU. Also look around all of the wiring harness to make sure it is not super hard and crusty if so then you might have shorted a wire out. Good old Mazda electronics don’t you love’m.

 

check the main fuse under the hood they guy i bought my car off of hooked the batt up back words and blew the main fuse, double check that.

--joe

 

I checked the fuses under the hood they are ok. I opened up the ecu and looked inside there were no burns or anything that looked fried, besides the car runs and i have driven it around the block, it just doesnt have spark coming from the trailing coil. would I be able to do this if the ecu is fried.

When you say run more grounds where do I run them from and where would I run them to.

thanks for the help

 

Well the first new ground would be from the (-) on the batt to the chassis. Second new ground I would do from the engine to the chassis/firewall. My extra ground there is a grounding post on the upper intake manifold in the area of the VDI (hard to explain with out a pic, S5 N/A). You could also do a ground from the block or tranny to the firewall just to double make sure. When my ECU fired my car ran to. But I fried it good it ran super bad could not hold an idle, back fired like crazy, etc. I have heard of people blowing them out and there cars running but just not well or not at all. When I opened the ECU I could not see any indications of burnt boards/wires ether so you might not be able to see it. Good luck

 

thanks for the help im going to borrow a coil from my friend tonight hopfully that is it if not then ill try the grounds and if that doesnt work ill try a different ecu.


Would a s5 ecu work for my s4 i dont think it will but i wasn't sure why

thanks again


ill let you know what happens then

 

Nope wont work, different sensors, maps, different compression levels, blah blah blah. If you do all that testing and swapping and it still does not work then you might want to look into is the CAS (crank angle sensor) is ok. In any RX-7 repair manual it has what wires to ohm out and what level they should be at. You might want to try that to. Just a thought.

 

ok I'm going to try that if the computer isn't the problem

thanks

 

ok I put in my friends coil and now it gets spark but it still doesn't run right, going to try a different computer tonight, hopfully thats the problem

 

man i am having the same damn problem car has been down for 8 months, the car will idle at 1200, when you try to give it some gas it drops down, the only way the rpms will go up is if you feather the throttle. now i did hook up the battery backwards and replaced the main fuse under the hood, and still the same thing, also my leading plugs are not firing. i'm gonna replace the leading coil and the main relay also my ecu is fried it has a burned transistor

 

Yep when I fired my comp that is what mine did to, but it back fired as well. Mine did not even iddle tho but the only way for it to rev was to feather it and bring up the RPM's slowly. Sorry bro

 

rotary racer mine has the same syptoms you are talking about what did you have to replace to get it back on track, i already got a ecu on the way and new wires, fd fuel pump changed out tps

 

When if get mine fixed Ill tell you, hopfully the computer im geting tonight that I thought was going in last night will be the problem

 

heres an update I finally got the computer and a trailing coil along with an afm. After I installed them the car won't even start. I was very cafefully when I installed the computer so that I didn't damage any wires, so I have no idea what is causing this new problem.